SECRET MESSAGES

File encryption is a popular means for ensuring the security and privacy of file-based data. An intruder who breaks through your firewall won’t be able to read your private files if they are encrypted, right? Actually, selective file encryption provided by utilities such as GnuPG covers some of your tracks, but it may not cover all of them. An intruder can still learn about your system – and maybe even reconstruct some of your file data – by snooping through secret files, temporary files, configuration data, and command histories. The /var/spool/cups directory, for example, could yield a treasure trove of data about files you might have printed in the past, and tools such as the Gnome Thumbnail Factory could be storing an unencrypted thumbnail of your encrypted images.

The recent revelations about NSA spying have sparked renewed interest in data encryption. Encrypting at the file level is quick and easy, but if you're looking for an extra dose of protection, try encrypting the whole block device.